*
   * @param key the non-null key whose value should be loaded
   * @return the value associated with {@code key}; <b>must not be null</b>
   * @throws Exception if unable to load the result
   * @throws InterruptedException if this method is interrupted. {@code InterruptedException} is
   *     treated like any other {@code Exception} in all respects except that, when it is caught,

    Object listener = new MyListener();
    ListenerCallQueue<Object> queue = new ListenerCallQueue<>();
    queue.addListener(listener, directExecutor());
    queue.enqueue(THROWING_EVENT, "custom-label");

    Logger logger = Logger.getLogger(ListenerCallQueue.class.getName());
    logger.setLevel(Level.SEVERE);
    TestLogHandler logHandler = new TestLogHandler();
    logger.addHandler(logHandler);
    try {

/**
 * Unit tests for {@link Callables}.
 *
 * @author Isaac Shum
 */
@GwtCompatible(emulated = true)
public class CallablesTest extends TestCase {

  @J2ktIncompatible // TODO(b/324550390): Enable
  public void testReturning() throws Exception {
    assertNull(Callables.returning(null).call());

    Object value = new Object();
    Callable<Object> callable = Callables.returning(value);

#### Merging pull requests ####

Due to Guava's nature as a subset of Google's internal codebase which is
automatically synced to the public GitHub repository, we are unable to merge
pull requests directly into the master branch. Instead, once a pull request is
ready for merging, we'll make the appropriate changes in the internal codebase

    RateLimiter r = RateLimiter.create(1);
    assertTrue("Unable to acquire initial permit", r.tryAcquire());
    assertFalse("Capable of acquiring secondary permit", r.tryAcquire());
  }

  public void testDoubleMinValueCanAcquireExactlyOnce() {
    RateLimiter r = RateLimiter.create(Double.MIN_VALUE, stopwatch);
    assertTrue("Unable to acquire initial permit", r.tryAcquire());

    waiter.start();
    waiter.awaitWaiting();

    future.set(1);
    waiter.join();
  }

  @J2ktIncompatible // TODO(b/324550390): Enable
  public void testSetNull() throws Exception {
    future.set(null);
    assertSuccessful(future, null);
  }

  public void testSetExceptionNull() throws Exception {
    try {

  /**
   * Returns the innermost cause of {@code throwable}. The first throwable in a chain provides
   * context from when the error or exception was initially detected. Example usage:
   *
   * <pre>
   * assertEquals("Unable to assign a customer id", Throwables.getRootCause(e).getMessage());
   * </pre>
   *
   * @throws IllegalArgumentException if there is a loop in the causal chain
   */

  /**
   * Returns the innermost cause of {@code throwable}. The first throwable in a chain provides
   * context from when the error or exception was initially detected. Example usage:
   *
   * <pre>
   * assertEquals("Unable to assign a customer id", Throwables.getRootCause(e).getMessage());
   * </pre>
   *
   * @throws IllegalArgumentException if there is a loop in the causal chain
   */

    attributes:
      label: Why do we need it to be improved?
    validations:
      required: true

  - type: textarea
    attributes:
      label: Example
      description: >
        Please provide an example usage of the feature that would be different with the improvement.
      render: java
    validations:
      required: true

  - type: textarea
    attributes:
      label: Current Behavior

  - type: textarea
    attributes:
      label: Expected Behavior
      description: What did you expect to happen?
    validations:
      required: true

  - type: textarea
    attributes:
      label: Actual Behavior
      description: What actually happened?
    validations:
      required: true

  - type: dropdown
    attributes:
      label: Packages